[1]} first proposed that the orbital motion of a binary system could account for the wiggling morphology of outflows. The authors found that the same description of a precessing jet model could be applied at a distance from the precession axis larger than the binary separation \(r_0\) . In this case, the half-opening angle is determined by the ratio between the orbital velocity and the total jet velocity \(\tan \beta = V_o/V_t\) . Also, the authors related the distance \(\Delta z\)  between a maximum and a minimum in \(y\)  (\(\Delta z\sim 23\)  for Cep E), to the separation \(r_0\)  of the two binary components:
\(\Delta z= \frac{2 \pi r_0}{\tan \beta },\) 
